Hidradenitis suppurativa GWAS in non-Hispanic white and non-Hispanic black ProCARE participants

Description:

We performed population-stratified analyses including a total of 919 hidradenitis suppurativa (HS) cases and 4,628 controls. Participants and the overall analytic framework are described in Broadaway (2025), British Journal of Dermatology (PMID: 40650879). Briefly, HS ProCARE participants were evaluated and diagnosed at an outpatient dermatology clinic, and individuals from the Add Health cohort served as population-based controls without HS-specific screening. We excluded individuals with genotype missingness >5% or sex discordance and removed variants with missingness >5%. We imputed  using the TOPMed Freeze 8 reference panel (hg38 build). We retained variants with imputation quality R² ≥ 0.8 within all four analysis groups (cases, controls, self-reported white, and self-reported black). We performed association testing using REGENIE v3.3 (--bt model).

The analyses underlying these summary results differ from the published results in the following ways:

- We restricted analyses to non-Hispanic White (NHW) and non-Hispanic Black (NHB) participants; other ancestry groups were excluded due to limited sample size. In the original analysis, participants were stratified as black and all other participants.

- We confirmed the absence of clear ancestry outliers for these two groups using principal components analysis (PCA).

- We performed population-stratified PCA analysis to include as covariates in the population-stratified (NHW and NHB) analyses.

- We included the following covariates: sex, age, body mass index (BMI), and the first 4 ancestry-specific principal components.

- Due to the additional screening, our sample sizes differ from the published sample sizes:

   NHW: 3976 total (415 cases, 3561 controls)

   NHB: 1564 total (497 cases, 1067 controls)

Corresponding author: Christopher J Sayed ([e-mail])